There is a quiet revolution underway in the US: energy codes are being adopted rapidly throughout the country, and the standards on which they are based are becoming increasingly stringent. Within the next decade, all buildings will be required to meet aggressive efficiency goals — in many cases, better than the required performance for LEED.
State Energy Codes are Gaining Ground
Energy codes specify minimum energy performance requirements for new construction and major renovations. Here are the trends in state energy code adoption (both commercial and residential) over the past eight years:
There are a few key takeaways from these charts.
1. The large majority of states have energy codes in place, and the number without codes is rapidly dwindling. As of December 2013, all but seven states have state-wide commercial energy codes, and all but eight have residential energy codes. Furthermore, for those states without state-level codes, an average of 52% of municipalities have filled the gap by adopting energy codes of their own.
2. States are quick to adopt to the latest versions of standards as they become available. In those states with energy codes in place, new standards quickly supplant older standards. This proves to be a significant driver of energy efficiency, as we’ll see below.
3. If current trends continue, by the end of the decade all states will have energy codes in place, and 85% will have adopted codes at least as stringent as ASHRAE Standard 90.1-2010 (the dark green above).
Standards are Improving
Concurrent with these trends, the standards and model codes on which state codes are based are becoming more efficient at an accelerating rate. The 2010/2012 versions of Standard 90.1 and the IECC (the International Energy Conservation Code) are 30% better than their 2004 counterparts.
To put that in perspective, a 30% improvement over an ASHRAE 90.1-2004 baseline would have earned you 10 points under LEED v2.2. Now that same level of performance is required for every commercial building in five states (and counting).
Relationship to LEED
These trends also affect LEED requirements. Most LEED rating systems reference ASHRAE Standard 90.1 for their energy performance credits. Newer versions of LEED reference newer versions of 90.1, so the minimum requirements keep getting higher.
The impact of this is significant. A recent study by KJWW Engineering Consultants examined the performance of a LEED v2.2 Silver office building and found that the base design wouldn’t meet the minimum energy requirements under LEED v4.
How does LEED compare to state energy codes? Already 75% of states require better energy performance than LEED v2.2 minimums (which references Std. 90.1-2004). And 10% of states already have the same minimum requirements as LEED v4 (which references Std. 90.1-2010). As states begin to adopt the newest version of this standard (Std. 90.1-2013), they will be requiring better energy performance than LEED v4.
If code adoption and efficiency trends continue, state energy codes may surpass LEED as a driver of high performance design by the decade’s end.
Impact on Architects
What does all of this mean for architects?
According to KJWW, a major shift will be required to continue achieving LEED points, as most of the “low hanging fruit” is already built into the new standards. Early, frequent energy analysis will be required to identify the best strategies and bundles to achieve target performance.
Late-stage optimization of mechanical systems won’t be enough to achieve significant reductions. A focus on building orientation, envelope, and facade design will be needed — elements that are firmly in the architect’s purview.
Architects who don’t want to be hemmed in by prescriptive code requirements will opt for performance-based compliance pathways. These allows greater flexibility, but also require the designer to both consider and quantify sustainable strategies during the design process.
Architects will be under pressure to deliver required performance without without cost increases. Fortunately, recent examples show that high performance doesn’t have to cost more.
As we’ve written in previous posts, we expect that these trends will drive increasing adoption of performance-based design among architects — as well as drive deep energy reductions across the building sector.